On 1071-08-26 the Seljuk Turks defeated the Byzantine army at the Battle of Manzikert and captured Emperor Romanos IV. The defeat weakened Byzantine military control in Anatolia and helped create conditions for sustained Turkic migration, settlement, and the gradual spread of Islam in the region.
By the late 11th century, the Danishmendids established a Turkish Muslim beylik (principality) in north-central Anatolia. Their courts and garrisons helped spread Muslim rule and settlement beyond the main Seljuk center, especially around Sivas, Tokat, and Niksar.
In 1077 a Seljuk-ruled state known as the Sultanate of Rum emerged in Anatolia. It became a key political framework for Islam in the region, supporting Muslim institutions while governing a population that still included many Christians and Greek speakers.
On 1176-09-17, the Seljuks of Rum defeated a Byzantine army at the Battle of Myriokephalon. This setback limited Byzantium’s ability to retake central Anatolia, reinforcing a long-term shift toward Turkish Muslim political dominance in the interior.
On 1243-06-26, Mongol forces defeated the Seljuk Sultanate of Rum at the Battle of Köse Dağ. After this, Rum’s rulers became dependent on Mongol power, and Anatolia entered a period of political fragmentation where many smaller Muslim-led states (beyliks) gained room to expand.
Jalal al-Din Rumi died in Konya on 1273-12-17, in the Seljuk capital of the time. His followers, especially his son and close students, organized teachings and practices that became the Mevlevi order, a Sufi network that later spread widely under Ottoman rule.
By 1299, Osman I’s frontier principality in northwestern Anatolia is commonly treated as the start of the Ottoman state. The Ottomans grew in a borderland zone where Muslim warriors, local converts, and allied groups competed with weakened Byzantine authority.
On 1326-04-06, Ottoman forces captured Bursa, their first major city, and used it as an early capital and administrative center. Controlling a wealthy urban hub strengthened Ottoman institutions and supported Muslim religious life through mosques, schools, and endowments.
On 1389-06-28, Ottoman and Serbian-led forces fought at Kosovo Polje, and the conflict ended in an Ottoman victory in many historical summaries. The battle weakened organized resistance in the central Balkans, bringing new populations and resources under a dynasty rooted in Anatolia’s Muslim frontier politics.
On 1453-05-29, the Ottomans conquered Constantinople, ending the Byzantine Empire. The city became the Ottoman imperial capital (Istanbul), and major institutions—including key religious buildings—were integrated into an Islamic imperial framework that shaped Anatolia’s religious and political life.
On 1514-08-23, Sultan Selim I defeated the Safavid state at the Battle of Chaldiran. The victory strengthened Ottoman control in eastern Anatolia and helped protect the empire’s Sunni religious order against a rival Shiʿi power, shaping political loyalties and religious policy in the east.
In 1516–1517, Selim I’s armies defeated the Mamluk Sultanate in a short war, including major victories at Marj Dabiq (1516-08-24) and Ridaniya (1517-01-22). This expanded Ottoman rule into Syria and Egypt and strengthened Ottoman claims to leadership in the wider Islamic world, marking a clear culmination of their ascendancy from an Anatolian frontier state into a leading Muslim empire.
Islam in Anatolia during Seljuk and Ottoman ascendancy (11th–16th centuries)